I realize this is an older thread, but you could remove the handles, buy a couple of cheap 3/8 ratchet extensions (yard sale, China tool store, Goodwill, etc.), cut the female ends off of the socket extensions, and weld them onto the ends of the jack shafts. Then you could carry a ratchet and use that to cycle the jacks up and down.

If it were me, I would remove the jacks altogether and install the kind that fits under the frame (just because I think it would look better).